With its long extremities, the spider has a range of ways to get around. Some models can even jump. This is possible using hydraulically operated bellows drives that serve as joints and keep limbs mobile. With no muscles to stretch their legs, these creatures build up high levels of body pressure that they then use to pump fluid into their limbs. Shooting fluid into the legs extends them. "We took this mobility principle and applied it to our bionic, computer-controlled lightweight robot. Its eight legs and body are also fitted with elastic drive bellows that operate pneumatically to bend and extend its artificial limbs," explains Dipl.-Ing. Ralf Becker, a scientist at IPA.
Researchers at IPA rely on generative production technologies, and specifically on selective laser sintering (SLS) of plastics, a 3-D printing process. In this process, step by step thin layers of a fine polyamide powder are applied one at a time and melted in place with the aid of a laser.
"We can use SLS to produce one or even several legs in a single operation; this minimizes assembly effort, saves materials and reduces the time it takes to build a robot. With the modular approach, individual parts can be quickly swapped as well. Our robot is so cheap to produce that it can be discarded after being used just once -- like a disposable rubber glove," Becker points out.